1. Field of the Invention
This invention relates to electronic monitoring and tracking of persons. More particularly, it refers to providing an all body worn low power active tracking apparatus integrated with a wireless network and central data base system resulting in advanced warning to victims, delivery of immediate instructional commands to offenders, and timely notification to an offender supervising and/or law enforcement agency should an offender and victim come within an unallowable proximity of one another or should the apparatus tracking the offender detect a violation or become disabled resulting in loss of contact with the offender's and/or victim's tracking apparatus.
2. Description of Prior Art
Currently, determining the location of a person or subject, such as an offender or victim, is possible outside the confines of their respective residence. An apparatus for determining such location is described in U.S. Pat. No. 5,731,757. This apparatus employs a tamper resistant body worn ankle wireless transmitter communicating with an associated tamper resistant portable tracking apparatus which must be carried by the offender. The portable tracking apparatus determines its location using Global Positioning System (GPS) satellites. The portable tracking apparatus communicates with a central data base system using wireless communications when portale and using land-line communications when placed in a charging stand at the subject's residence or work location. Algorithms in the offender's portable tracking apparatus executing on the processor compare the offender's current location against a schedule of location rules stored in the memory of the offender's portable tracking apparatus. The purpose of a two part tracking device is to place the low power transmitter tag device as the body won component and the high power consumption devices (i.e. GPS receiver card, processor and memory card and wireless transceiver and data modem card) as an integrated portable unit that requires periodic recharging. The body worn transmitter tag device does not require battery recharging or replacement for extended time periods. If the subject forgets to transport the portable tracking device as the subject's location changes (i.e. from home to work), then the ability to track the subject is lost.
When the offender's portable tracking apparatus detects that the offender has violated a safety perimeter established at a static location for the victim, such as the victim's home or work location, the offender's portable tracking apparatus establishes a wireless communications connection with the central data base system to report the violation when in active tracking mode. The central data base system in turn communicates with the offender's supervising agency, law enforcement agency and the victim's portable tracking apparatus by a wireless communications connection to notify the supervising agency, law enforcement agency and victim of the violation. This frequent communication in order to establish offender or victim location is referred to as "active tracking" as opposed to "passive tracking" which is a batch download of the subject's movements during a period of time such as daily when the offender returns to his or her residence and has access to a land line telephone.
Current conventional GPS offender tracking receivers are board level products comprised of multiple integrated circuit chips. Multiple integrated circuit chips consume more power than a single integrated circuit chip with the combined capabilities of the individual integrated circuit chips. Conventional GPS receivers can determine location (latitude and longitude) outdoors and indoors (such as vehicles and buildings) provided there is a window with a clear view of the sky within several feet of the GPS receiver's antenna.
Clearly, size, weight and power are critical requirements for any body worn tracking device. Recent technology affords the ability to combine the body worn transmitter with the portable tracking device described in U.S. Pat. No. 5,731,757 to provide an all body worn device and provide small size and low weight. Other recent technology affords a low power body worn tracking solution through semiconductor SOI technology, matching filter GPS receiver techniques, connectionless oriented digital wireless communication services, miniature watch crystal type GPS antenna and current miniaturized processor and memory devices.
U.S. Pat. No. 5,497,149 describes a body worn locating device that is recharged using a plug in wire battery charging interface to an external power source such as a wall power outlet. With technology known at the time of U.S. Pat. No. 5,497,149 the device described in this Patent, if constructed, would require large batteries and frequent batters recharging or battery replacement due to the amount of power consumed from conventional GPS receivers and cellular phone calls to periodically determine the location of the subject wearing the device, especially where unwilling subjects such as released criminal offenders are wearing the locating device and frequent (i.e. several times an hour) location points are desired. Other personal tracking devices found in U.S. Pat. No. 5,712,619, U.S. Pat. No. 5,742,509, U.S. Pat. No. 5,742,233, U.S. Pat. No. 5,528,248, U.S. Pat. No. 5,731,785, U.S. Pat. No. 5,714,931, U.S. Pat. No. 5,731,785 and U.S. Pat. No. 5,625,668 do not address the low power technology required to implement a non removable body worn locating device in a small, lightweight form factor that is either rechargeable using non contacting external power sources or can function for extended periods of time on a replaceable battery.
There exists a need to combine the functionality of the tamper resistant portable tracking apparatus and the body worn ankle transmitter described in U.S. Pat. No. 5,731,757 and the functionality described in applicant's U.S. patent application Ser. No. 09/082313 into a single body worn tamper resistant apparatus that is capable of being powered for long time periods on the subject's body without the need of assistance by the subject wearing the apparatus attaching an external power source to the apparatus.
In the case of small size, light weight and low power, there exists a need for a high density low power FPGA integrated circuit for the discrete digital functions of processor, memory, serial/parallel communications, analog input/output and digital input/output. In the case of assured message delivery, end-to-end verification of data delivery is needed to assure victims are warned, supervising and law enforcement agencies are notified and the central data base system stores offender and victim location, health and status data, especially where violations have occurred.